Brake for loom letoff mechanism



March 11, 1947;. H T 2,417,379

BRAKE FOR LOOM LET-OFF MECHANISM Filed Feb. 12, 1945 zzg/ a 55 k9 3 a I a: I r

Patented Mar. 11, 1947 2,417,37 9 BRAKE FOR LOOM LETOFF MECHANISM Andrew B. Shelton,

Columbus, Ga., assignor to A. B. Shelton Corporation, a corporation of Georgia Application February 12, 1945, Serial No; 577,433

1 Claim.

This invention relates to let-elf mechanisms for looms.

In let-off constructions at present in use the ratchet which progressively rotates the warp beam is restrained from free rotation by means of a friction clamp which encircles a friction hub or drum, and the latter is fixed to the ratchet between the ratchet and a spur gear with a rock arm outside of the spur gear so that when the friction clamp must be replaced it is necessary to remove the spur gear and the rock arm. It is, therefore, an object of this invention to provide an improved friction clamp or brake which may be removed without removal of adjacent parts so that the renewal of the friction lining can be accomplished with a minimum of lost time.

Another object of this invention is to provide a brake for loom let-01f mechanism which is formed at its lower end with an open fork engaging with the rock shaft correlated with the yarn mass on the warp beam so that the arm may be quickly disengaged from the rock shaft without disconnecting other parts associated with the rock shaft, or other elements carried by the pinion shaft which drives the warp beam gear.

A further object of this invention is to provide a device of this kind which is simple in construction and which may be incorporated with the present construction of looms without change in the present parts, and will reduce the stoppage time of the loom for replacement of the friction lining to a minimum.

In the drawings:

Figure 1 is a detail side elevation of a device constructed according to an embodiment of this invention mounted on the related portions of the loom which are shown in section and partly broken away.

Figure 2 is a fragmentary top plan of the device.

The warp beam is adapted to be progressively rotated and the amount of rotation is controlled by making movement of a lever or arm II the upper end of which engages the yarn mass on the warp beam as shown in Patent No. 647,815. The shaft It has loosely mounted thereon a ratchet fragmentarily shown at I and fixedly secured to said ratchet is a brake drum I2 which is concentric of the shaft I0 and this drum is encircled by means of a friction clamp or brake band, gen

erally designated as I4. The brake band I4 includes a substantially semi-circular band member I3 which is formed integrally With an elongated arm I5. The band 54 also includes a second arcuate member I6 which is pivotally mounted at one end between a pair of ears 1?, carried by the lower end of the member I 3. The arouate member I6 is formed with a reduced thickness hinge lug Ita engaging between the ears I1 and mounted on a pivot pin IIa which extends between the ears ITI. The hinge construction is such that the arcuate member I6 may be swung substantially from an operative to an inoperative position. The band member I3 has extending from the free end thereof, a lug I8 which is formed with an opening I9 through which a band tensioning bolt 20 loosely engages. The bolt 20 also loosely engages through an opening 2! which is formed in a lug 22 carried by the free end of movable band member I6.

A band clamping lever 23 is pivotally mounted as at 24 on the bolt 20, being formed with a cam 25 engaging against the adjacent face of lug 22. Bolt 20 is threaded at its opposite end, as indicated at 26, and a nut 27 is threaded on the threads '26 and bears against a band tensioning spring 28 which is positioned about the bolt 20 between the nut 2'! and lug I8.

The lever 23 is formed with an outwardly extending handle 29 and the lever 23 together with the bolt 20, is held against rotation by means of spaced ears 3!) and 3| I carried by the movable band I6 and engaging on opposite sides of lever 23. A friction band 32 is secured to the inner or concave side of the band member I3, and extends outwardly, as indicated at 33, on the inner side of lug I 8. Bolt 20 loosely engages through the extended band portion 33. A second brake band 34 is secured to the inner side of the band member I6, and these two bands or linings 32 and 34 are adapted to normally engage the brake drum I2, so that ratchet I0 is held against free rotation.

The lower end of arm I5 is forked or of U-shape being provided with spaced arms 35 and 36 engaging on opposite sides of the rock shaft 31 which is carried by the operating member I I.

As shown in Patent 647,815, the normal position of the brake band arm I5 is on the inner side of a second arm, and there are gears on shaft I0 outwardly of these two arms.

With prior constructions it has been necessary to remove said outer arm in order to reline the brake band and to remove such arm it has also been necessary to remove the related gears.

However, with a let-ofi mechanism brake contogether at the other end; an arm fixed at one I means releasably connecting said band members struction as hereinbefore described, the brake end to said first band member and being forked band may be opened as shown in dotted lines in at the other end, said forked end embracing said ure 1, bolt 20 being unthreaded from nut 21 rockshaft to prevent rotation of said brake band; and then the op n mbly may be swung to 5 the construction being such that when said ret r ht a d lift d om rockshaft 3 In the leasable connection is released said second band open position of the assembly the bra Will e member may be swung to a position wherein both d po e ho l o ne vside f e d and dash band members lie wholly on one side of a straight C te l ne o Sha t s sh in Figure 50 line passing through the center of said pinion that the assembly can then be removed from the haft, whereby id brake ma be removed from loom w tho t disc n e y other p of the the loom without removing any other parts of said loom. The brake lining may then be applied to 1 1-,.. mechanism the inner sides of the brake band members and NDREW B, SHELTON. the lever construction reassembled; f

It will, therefore, be apparent that to renew REFERENCES CITED the brake lining which must be renewed rather The following references are of record in the frequently, no additional parts need be removed r- I from the loom. This provides, therefore, for elimme of thls patent inating a considerable loss of time which has UNITED STATES PATENTS heretofore been necessary in relining these Number Name Date e V I 1:2, 1 m it 7 Y 647,815 Draper A r. 1'1, 1900 In a loom warp beam let-'ofi mechanlsm of the 9% Roper j NOV 24 1903 type having a beam gear, a pinion shaft, a ratchet 39559 H me}; Jan 12 1909 loosely mounted on said pinion shaft and a rock- 25 5 1 M dm Sept, 29 1885 o shaft: a brake including a brake drum fixed to said ratchet; a brake band surrounding said O N PATENTS brake drum and comprising a first band member, i

a second band member, means pivotally connect- Number v a 901mm D ing said band members together at one end, 30 265194 Brmsh July) 1927 

